Panel mounted resistor



July 16. 1968 0. L. RAKOWSKY 3,393,391

PANEL VOUNTED RESI STOR Filed Aug. 15, 1966 United States Patent3,393,391 PANEL MOUNTED RESISTOR Darwin L. Rakowsky, Columbus, Nelm,assignor to Dale Electronics, Inc., Columbus, Nebr., a corporation ofNebraska Filed Aug. 15, 1966, Ser. No. 572,431 7 Claims. (Cl. 338-271)ABSTRACT OF THE DISCLGSURE A resistor having one end secured to a metalhousing by means of a threaded fastener thereby causing the housing tobe common to one terminal such that the housing serves as a terminal ofthe resistor.

An object of this invention is to provide a resistor which has a minimumnumber of parts.

A further object of this invention is to provide a resistor which iseasy to manufacture.

A further object of this invention is to provide a resistor which iseconomical of manufacture.

A further object of this invention is to provide a resistor whichpermits the reduction in overall length thereof thereby allowing forcompact assembly.

It is a further object of this invention to provide a resistor whereinonly one terminal protrudes from the housing thereby allowing for asolid ceramic core which will result in an increase of the resistorpower rating and a stronger resistor body or core.

A further object of this invention is to provide a resistor wherein oneend of the resistance means is secured to the housing which permits theresistor to withstand severe shock.

A further object of this invention is to provide a more stable resistordue to the fact that the hot spot of the resistor will be uniform to theend of contact rather than at the center thereof.

A further object of this invention is to provide a resistor housingwhich can be mounted on a panel board or chassis by utilizing aninternally threaded hole or a clearance hole and nut.

A further object of this invention is to provide a resistor whereinintimate contact is created between the resistor-housing-mounting panelwhich provides a greater amount of heat dissipation.

A further object of this invention is to provide a resistor which isdurable in use.

These and other objects will be apparent to those skilled in the art.

This invention consists in the construction, arrangements, andcombination of the various parts of the device, whereby the objectscontemplated are attained as hereinafter more fully set forth,specifically pointed out in the claims, and illustrated in theaccompanying drawings in which:

FIG. 1 is a perspective view of the resistor;

FIG. 2 is an end view of the resistor as would be seen on line 2-2 ofFIG. 1;

FIG. 3 is a side view of the resistor;

FIG. 4 is a longitudinal sectional view of the resistor; and

FIG. 5 is an exploded perspective view of the resistance means and endcap assemblies.

The numeral generally designates the resistor of this invention andincludes a hollow metal housing 11 and a resistance means 13. Housing 11includes a body portion 15 having a cylindrical cavity 17 formedtherein, and end portions 19 and 21. Housing 11 is provided with anexternally threaded portion 23 adjacent end 21 and is provided with aninternally threaded opening 25 formed therein at the center of end 19.Housing 11 is provided with a plurality of fin members 27 extendingradially outwardly from body portion 15 as illustrated in FIGS. 1, 3 and4. A fin member 29 also extends radially outwardly from body portion 15and has a thickness greater than each of the individual fin members 27.The various fin members on housing 11 are spaced apart as seen in thedrawings and may be of hexagonal shape in section to facilitate theattachment of the resistor to the mounting panel or chassis.

Resistance means 13 is comprised of a solid ceramic core 31 which mayhave a resistance film provided thereon or a resistance wire meansmounted thereon in con ventional fashion. A cap means 33 is mounted onone end of resistance body 31 and is secured thereto by any convenientmeans. The cap means 33 is electrically connected to one end of theresistance means 13 and has an externally threaded stud portion 35extending therefrom. A cap means 37 is mounted on the other end ofresistance body 31 and is secured thereto by any convenient means. Capmeans 37 is electrically connected to the resistance means and has aterminal assembly 39 secured thereto and extending outwardly therefromas best seen in FIGS. 4 and 5. The cap means 33 and 37 are electricallyconnected to opposite ends of the resistance means on the resistancebody 31.

The resistor 10 is assembled by simply inserting resistance means 13into cavity 17 and threadably securing resistance means 13 to housing 11by causing stud means 35 to be threadably received by opening 25 in end19 of housing '11. This mode of securing resistance means 13 to housing11 causes intimate electrical contact between cap means 33 and housing11 only at end 19. A suitable insulation means or potting compound isthen poured, transferred or injected into the cavity 17 aroundresistance means 31 as best illustrated in FIG. 4 to completely insulatethe remainder of the resistance means from housing 11. As seen in FIG.4, terminal assembly 39 protrudes outwardly of housing 11 at end 21. Ifdesired, end 21 of housing 11 could be constructed to threadably receivethe stud 35 thereby allowing terminal assembly 39 to protrude outwardlyof housing 11 from end 19. In other Words, the terminal assembly 39would be positioned opposite to the externally threaded portion 23 onthe housing 11.

The resistor 10 is then secured to a mounting panel 42 or chassis bysimply extending threaded portion 23 through a suitable aperture thereinand threadably securing a nut means 41 thereon. The aperture in themounting panel or chassis could also be internally threaded and adaptedto threadably receive the threaded portion 23 which would eliminate theneed of a nut 41. Terminal assembly 39 would then be electricallyconnected to the desired circuit. In effect, the housing 11 serves asone terminal of the resistance means while terminal assembly 39 servesas the other terminal. This results in intimate contact ofresistor-housing-mounting panel thereby permitting a greater amount ofheat dissipation. In conventionally housed resistors, the entireresistor is electrically insulated from the housing and the insulatingcompound permits less heat dissipation. The construction of resistor 10results in a net reduction of necessary parts and is extremely easy tomanufacture. The insulating process referred to above could beaccomplished by any potting process such as pouring or filling thecavity, with a resinous fluid and then curing the resin causing thefluid to become solid. The configuration of the resistor permits areduction in overall length thereby allowin for compact assembly. Thepanel mounted resistor of this invention has only one terminalprotruding from the housing, thus permitting the use of a solid ceramiccore. This results in an increase of the resistor power rating and astronger resistor body or core. The resistance means, being fastened tothe housing, will withstand severe shocks or jolts. The limiting factorof the power rating of a resistor is the temperature of the hot spot ofthe resistor which is usually located at the center thereof. In thisinvention, the temperature will be uniform to the end of contact, thusprovi-ding a more stable resistor.

Thus from the foregoing it can be seen that the device accomplishes atleast all of its stated objectives.

Some changes may be made in the construction and arrangement of myresistor without departing from the real spirit and purpose of myinvention, and it is my intention to cover by my claims, any modifiedforms of structure or use of mechanical equivalents which may bereasonably included within their scope.

I claim:

1. In a resistor,

a hollow metal housing having opposite ends,

said housing having one of its ends externally threaded and adapted tobe received by an opening in a supporting means for threadableattachment thereto,

an elongated resistance means in said hollow housing and having aterminal means at one end thereof extending outwardly of one end of saidhousing,

said resistance means being threadably, detachably and electricallyconnected at its other end to the other end of said housing,

and insulation means between said housing and said resistance meansalong the length thereof.

2. The resistor of claim 1 wherein said resistance means is comprised ofa resistance body having first and second electrical conductive capmeans secured to the opposite ends thereof, said first cap means havinga threaded stud extending therefrom which is threadably secured to saidother end of said housing.

3. The resistor of claim 2 wherein said second cap means includes saidterminal means and which is adapted for lead connection.

4. The resistor of claim 1 wherein said housing includes a body portionwhich is hexagonal in section.

5. The resistor of claim 4 wherein said body portion has a plurality offin members extending therefrom.

6. The resistor of claim 1 wherein said housing has an internal cavityhaving a diameter greater than said resistance means and has a lengthless than said resistance means, said housing having a shoulder portionthereon laterally of said externally threaded portion.

7. The resistor of claim 1 wherein said resistance means extends onlyfrom said one end of said housing.

References Cited UNITED STATES PATENTS 1,910,866 4/1933 Van Nostrand338-271 X 2,492,755 12/1949 McCollum 338-271 X 2,640,132 4/1953 Thom338-268 X 2,768,267 10/1956 Pass 338-332 X FOREIGN PATENTS 553,30211/1929 Germany.

LARAMIE E. ASKIN, Primary Examiner.

E. GOLDBERG, Assistant Examiner.

